Sierra Universal Rectifier 18-99429 - 20 Amp - Replaces 474470, 650450, 617450 - Fits 2/3/4 Cylinder Outboards

The Sierra 18-99429 is a 20 amp universal rectifier engineered as a direct replacement for the charging system on 2, 3, and 4 cylinder outboard engines. The rectifier converts the AC output from the outboard's stator into DC current to charge the battery, making it a critical component for reliable electrical system operation. It is built as a drop-in replacement covering a wide range of outboard applications, cross-referencing to numerous OEM part numbers so boaters can find the correct replacement using either the original engine manufacturer's number or the Sierra part number 18-99429.

This rectifier is compatible with 2 cylinder outboards from 9.9 to 50 HP, 3 cylinder outboards from 50 to 90 HP, and 4 cylinder outboards from 100 to 140 HP. It is a straightforward bolt-in replacement for a failed or underperforming rectifier, restoring proper charging output and preventing battery drain or overcharging caused by a degraded unit. Compact and lightweight at 0.1 pounds, it is sized to fit within the existing mounting location on the outboard's electrical panel without modification.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99429
• Amperage: 20 Amp
• Weight: 0.1 pounds
• Product Dimensions: 2 x 2 x 2 inches
• UPC: 808282394608
• Category: Chrysler Outboard Electrical System

Fitment

• 2 cylinder outboards, 9.9 to 50 HP, 1975-1992
• 3 cylinder outboards, 50 to 90 HP, 1975-1985
• 4 cylinder outboards, 100 to 140 HP, 1976-1989

Replaces (OEM)

• 474470
• 650450
• 510450-1
• 617450
• 87-F650450
• FA617450
• FA650450
• F475470
• F510450
• F510450-1
• F404470
• F404470-1
• F617450
• F650450
• F684450
• F684458
• FK650450

Frequently Asked Questions

What does the Sierra 18-99429 rectifier do? It converts the AC output from an outboard engine's stator into DC current to charge the battery, and is rated for 20 amp output.

What outboard engines is the 18-99429 rectifier compatible with? It fits 2 cylinder outboards from 9.9 to 50 HP built 1975-1992, 3 cylinder outboards from 50 to 90 HP built 1975-1985, and 4 cylinder outboards from 100 to 140 HP built 1976-1989.

Is the Sierra 18-99429 a direct OEM replacement? Yes, part number 18-99429 is designed as a direct replacement, cross-referencing to OEM numbers including 474470, 650450, 617450, and 510450-1 among others.

What OEM part numbers does 18-99429 replace? It replaces 474470, 650450, 510450-1, 617450, 87-F650450, FA617450, FA650450, F475470, F510450, F510450-1, F404470, F404470-1, F617450, F650450, F684450, F684458, and FK650450.

How much does the 18-99429 rectifier weigh? The Sierra 18-99429 rectifier weighs 0.1 pounds.

What are the dimensions of the 18-99429 rectifier? It measures approximately 2 x 2 x 2 inches.

Will this rectifier work on a 3 cylinder outboard? Yes, the 18-99429 covers 3 cylinder outboards from 50 to 90 HP built 1975-1985.

Does the 18-99429 rectifier require any modification to install? No, it is a bolt-in replacement sized to fit the existing rectifier mounting location on compatible outboards.

Is a mounting bracket or hardware included with the 18-99429? The rectifier itself is the unit supplied under part number 18-99429; no additional components beyond the rectifier are specified.

What is the amperage rating of the Sierra 18-99429? The 18-99429 is rated at 20 amps.